Monday, November 26, 2007

Non-Events

Opher points out that absence requires a context. His examples involve something not happening within a defined time period. (no financial transaction today, pizza hasn't arrived within 40 minutes). Tim points out that Opher's examples can all be modelled as clock events - the event that triggers action is the end of the period, occurring when the system is in the no-transaction or no-pizza state.

But there are more complex cases where the context for the negation is not a precisely defined time period. Consider Lacan's story of the three prisoners.

The prison governor invites three prisoners into his office and shows them three green discs and two red ones. Then he puts a green disc on each prisoner's back. Each can see the disc on the other two prisoners' backs. The first one to deduce the colour of the disc on his own back will be granted his freedom.

The correct deduction appears to depend on the hesitation of the group. "If I had a red disk, then each of the other prisoners would not hesitate to deduce immediately that he was green. Since neither has done so, I must also have a green disk." In other words, one prisoner makes a deduction based on the failure of the other two prisoners to make a deduction. In other words, non-deductions or absent events.

But this failure cannot be a clock event. The prisoners are not watching the clock, they are watching one another.

Questions of the timing of decisions are critical in a number of event-driven (and non-event-driven) situations. For example, stock markets fluctuate according to a wide range of events and non-events. An investor may buy or sell a particular stock based on the observation that other investors have not been buying or selling that particular stock. In a lot of situations, the best time to make a decision is the day before everyone else comes to the same conclusion.